1. Field of the Invention
The present invention relates to pedestal closure assemblies for storing power and telecommunications equipment, and more particularly to pedestal closure assemblies having upper and lower housing sections fastened together with locking mechanisms configured to keep the sections securely connected and to allow for access to the internal equipment, and for easy and secure manual assembly and disassembly.
2. Description of the Related Art
Telecommunications, cable television, power distribution equipment and the like, including primary cable loops, terminal blocks, and connections between a primary cable loop and a terminal block are commonly located out-of-plant and subject to ambient weather conditions. Since the necessary equipment is located outside, a protective covering is required to safeguard the equipment from human interference as well as from the environment. Therefore, such protective covering must provide structural as well as environmental protection.
Typically, the protective covering is produced in the form of a pedestal. The pedestal structure includes a housing with a sufficient volume occupying a small area and placeable in a convenient working orientation for housing the aforementioned equipment. Inside the housing, cable pairs may be interconnected to each other. Such interconnections are made at a connector block which is mounted to a universal mounting plate inside the pedestal closure assembly. The connector block includes a number of terminals, and the pairs of wires in the cable are stripped of their insulation and connected to the terminals.
A base section of the closure housing is recessed and secured in the ground, and has a passageway to permit underground cables to extend therethrough. The cables extend through the base section and are covered by a top section of the housing which attaches to the base section. The pedestal closure assembly, when assembled and installed, should have sufficient structural strength to resist minor impacts as well as other environmental conditions such as wind, snow accumulation or precipitation impact.
Presently, commercially available pedestal closure assemblies are primarily constructed of metal and the upper and lower sections are held together by, for example, positioning a clamping bracket around the lower section of the pedestal closure assembly, and then fitting the upper section of the housing over the lower section and fastening it to the clamping bracket by a bolting means or a bayonet-locking means.
Another technique previously used to assemble metallic upper and lower sections of a pedestal entails a screw-clamp method which requires positive location of a clamping means on the pedestal closure assembly. This can cause marring of the finish when the pedestal closure assembly is made of metal, thus causing rusting and corrosion after prolonged exposure to the elements. If the pedestal closure assembly is non-metallic, the pressure of the fasteners, due to their geometrical shape and small contact area, can lead to indenting or fracture of the pedestal closure assembly. Finally, if the fasteners are not sufficiently tightened, the position of the clamp may change causing the closure to become disassembled, especially in the presence of extreme physical and environmental impact, such as flood-level waters or deep snow.
Another technique involves the placing of screws in the lower housing section. The screws are then screwed radially toward the upper housing section of the pedestal closure assembly with opposing screws providing the locking action. This technique is not very efficient as the tightening of one of the screws may cause the other screws to become loose. With this technique, therefore, it is difficult for the installer to know if and when a tight fit has been made. Quite often, a chain is used as an additional restraining device to prevent the top and bottom sections from coming unlocked and apart.
U.S. Pat. No. 3,812,279 discloses a cable television housing with a lockably joined cover and base locked together by a rotatable shaft having an L-shaped keeper mounted on the cover that fits in a longitudinal opening in a bayonet opening in the base.
U.S. Pat. No. 3,854,582 discloses a container with a cover, with the container having locking L-shaped lugs and the cover having complementary slots to receive the lugs. The container and cover are rotatable so as to allow the lugs to be moved into and removed from the slots on the cover.
U.S. Pat. No. 3,858,755 discloses a meter box with a cover having a biased snap-lock. The locking member includes a cammed latch for engaging a flange on the box body; the locking member also includes a slightly flexible spring section.
U.S. Pat. No. 3,872,234 discloses an electrical cable pedestal structure with a top and bottom section connected by having bolts received in open end slots in each side wall of the bottom section in tandem with a stake for further support.
U.S. Pat. Nos. 3,952,908 and 4,065,020 disclose a meter box and two-part rotatably locking cover. The cover is locked into place by using three (3) selectively engaging flanges or protrusions and slots, with the flanges located on the cover and the slots positioned on the meter box.
U.S. Pat. No. 4,005,253 discloses a grade-level enclosure for electrical apparati with a cover and base section connected by a threaded tube and screw mechanism.
U.S. Pat. No. 4,326,395 discloses an electric enclosure locking assembly which consists of an attaching bolt that secures an adjustable bracket to the cover of the enclosure, a locking shield which overlies and prevents removal of the attaching bolt, and a removable lock bolt which secures the locking shield to the cover.
U.S. Pat. No. 4,365,108 discloses a secondary power pedestal with housing and cover sections that could be attached with either a padlock or other cooperating hasp and receptacle members, such as a threaded socket for a lock bolt.
U.S. Pat. No. 4,892,978 discloses self-supporting pedestal with a top cover and base unit kept together by inserting a pin through locking openings formed on locking ribs on the base unit and also through the associated locking openings formed on the channeled bosses of the top cover.
U.S. Pat. Nos. 5,055,636 and 5,235,134 disclose a sealed reenterable splice enclosure with a top and bottom section attached by a padlock and spline mechanism.
U.S. Pat. No. 5,059,748 discloses a cable splice enclosure with a base and domed cover that are attached by an O-ring and circular clamp mechanism.
U.S. Pat. No. 5,308,923 discloses an enclosure assembly that is mounted on telephone poles or exterior walls of buildings and the like with multiple latches and flanges integral with the cover section and base section of the assembly. A support bracket is apparently needed to secure the cover and base sections together when the assemble is attached to a pole or exterior wall and the like.
U.S. Pat. No. 5,777,268 discloses an environmentally sealed splice closure for buried telecommunications cables with a cap section and two base sections, base sections being connected by inserting locking pins into complementary slots on each base section, and cap section and base section being held together by base snap fingers received in cap finger slots.
In some instances, a traditional combination padlock is used to keep the upper and lower sections of the housing together. A closed hook is included on either the upper or lower section of the housing to engage the padlock. This method of locking tends to cause many problems, especially in inclement weather. Oftentimes, after a snow or freezing rain, the padlock is frozen such that the combination wheel cannot be turned. Even when a non-combination padlock is used, frozen water can get into the lock and prevent a key from opening the padlock.
Additionally, costs of fabricating metal pedestal closure assemblies are higher than for non-metallic ones. Furthermore, since metal pedestal closure assemblies are relatively heavy, it takes costly and time-consuming labor to install them correctly and to ensure that they do not begin to lean after installation and extended physical and environmental impact in a support medium.